Polyvinyl chloride resin (PVC resin), which has been widely used for building materials such as window frames, has entailed a problem in that a large amount of environmentally harmful substances such as dioxins are generated during burning or extrusion processing. Also, heavy metal ions such as cadmium stearate (Cd—St) or lead stearate, which have been used as thermal stabilizers for the PVC resin, are regulated, because they act as human hormone-disrupting chemicals. Also, these ions have been identified as main factors causing problems such as sick building syndrome. Also, polyvinyl chloride resin has shortcomings in that, because it becomes discolored during the production thereof due to very poor thermal stability, it is difficult to recycle, and it has low weather resistance when used as an exterior building material, and is poor with respect to its ability to be colored with a pigment.
Attempts to improve such shortcomings in the PVC resin have been ongoing. For example, Korean Patent Registration No. 10-020014 made an effort to improve surface embossing during processing of the prior polyvinyl chloride resin, and Korean Patent Publication No. 2003-0057963 enhanced painting properties by adding fluoride resin in order to improve weather resistance. Also, Korean Patent Publication No. 2001-0096666 utilized a mixture of an ethylene copolymer and an ethylene terpolymer to prevent the production of environmentally harmful substance dioxin, but only substitutes for soft polyvinyl chloride resin.
Despite such efforts, the environmental problem caused by the PVC resin has still not been solved. For this reason, there has been a continued demand for an environment-friendly resin substitute for PVC, which does not generate environmentally harmful dioxin substances when burned and, at the same time, is prepared without using heavy metals such as the environmentally harmful substances lead or cadmium. Also, there has been a continued demand for a resin substitute for PVC, which does not cause the environmental problem caused by PVC resin, which can be processed (e.g., extruded and bonded) using existing PVC production equipment, and which has excellent properties of weather resistance and recyclability.